In the interest of preserving views of the national monuments and the District’s symbolic skyline, Congress should keep in place the height restrictions that have governed the scale of D.C. buildings for more than a century, according to recommendations from the National Capital Planning Commission.

The commission will make its draft recommendation on Thursday, as it reports on the preliminary findings of a study of the federal interests in changing the 1910 Height of Buildings Act.

House Oversight and Government Reform Chairman Darrell Issa, R-Calif., requested in October 2012 that the NCPC and the city work jointly to examine how changes to the height act could affect the future of D.C. Issa has suggested there could be commercial and economic benefits to allowing some buildings to stand taller. Current standards mostly limit building heights in business areas to the width of the adjacent street plus 20 feet. There is also a general height limit of 130 feet, extended to 160 feet along parts of Pennsylvania Avenue.

NCPC Executive Director Marcel Acosta’s report focuses specifically on the national and federal development needs, as well as the federal interest in the “symbolic, historic and urban design form of the national capital.”

It finds that changes to the height act within the L’Enfant City — the central part of the city with the highest concentration of monuments and museums — and the low green hills surrounding it “may have a significant adverse effect on federal interests” and affect the character of central streets and public spaces. The conservatively framed report also points out that many of D.C.’s buildings are not built up to their full height potential under the height act and suggests that “viewshed protections merit further study.”

Despite the fact that D.C. has had one of the nation’s strongest commercial and residential development markets and a rapidly growing population, the NCPC finds “no specific federal interest in raising heights to meet future federal space needs” and points out that the Office of Management and Budget predicts a “flatline” in demand for federal agency office space.

The NCPC leaves the door open to one of the issues raised by stakeholders — lifting the height act’s ban on human habitation of penthouses — saying that changes have no impact on federal interest, as long as they include specific protections on federal buildings and prohibitions on the “stacking of penthouses.”

Detailed urban design and economic studies that build the case for the city’s approach to modifying the height act are currently being prepared by the District’s Office of Planning, according to Chief of Staff Tanya Washington Stern. Stern said the city hopes to release its draft recommendation later this month, after a consultation with the mayor’s office.

Both agencies shared models of potential changes to D.C.’s skyline with the public during a series of meetings earlier this summer and received verbal and written feedback, much of which appeared critical of a taller D.C. Next up in the process is another 30-day period for public review. The NCPC expects to take final action to approve the report at its Nov. 7 meeting, then present its findings to the committee.